Draft key for car couplers



May 26, 1931.

E, H. SCHMIDT DRAFT KEY FOR CAR COUPLERS Qriginal `Filed Oct. 6, 1927 @norm/woz:

Patented May 26, 1931 PATENT OFFICE OHIO, ASSIGNOR- TO NATIONAL CLEVELAND, OHO, A. CORPORA- DRAFT KEY FOR CAR COUPLERS Application lcd GCtOber 6, 1927, Serial No. 224,316. Renewed April 16, 1929.

My invention relates to draft keys for car couplers. The draft keys now employed make no provision for lateral angling or radial movement of the coupler relative to the yoke except such as is incidentally provided by the clearance between the parts. This results, how-ever, when the coupler is angled relative to the yoke, in an unequal bearing of the draft key on the yoke arms, frequently all of the draft strains being transmitted from the coupler to the yoke through only one of the yoke arms, or one side of the yoke, because the key is angled in such a way as to have a bearing upon only one of the yoke arms. This, obviously, transmits an unbalanced application of force through the walls of the coupler key slot to the key, and the resulting transmission of the draft stresses through one side or arm of the yoke imposes 100% more load on that arm than it would bear if the load were equalized. This is a prolific cause of yoke, coupler shank and draft key failures.

My invention is directed to eliminating such difficulties and to providing an equal bearing on both yoke arms regardless of the angularity of coupler and yoke. I accomplish this by so constructing the draft key that it is capable of radial movement relative to the coupler, and at the same time provides a firm and equal bearing on both arms or .sides of the yoke. My invention also comprises various features which I shall hereinafter describe and claim.

In the accompanyingdrawings, Fig. 1 is a. horizontal section of a coupler shank and yoke connected by a radial draft key embodying my invention; Fig. 2 is a longitudinal vertical section on line II-II of F ig. 1; Fig. 3 is a rear elevation of a portion of the main key part showing the recess therein; and Fig. l is a front elevation of the equalizer bearing portion of the key.

Referring more specifically to the drawings, I have shown my invention applied to the coupler shank 2 of a standard D-coupler which has the usual key slot 3 extending transversely therethrough with the usual front and rear concave bearing walls l and 5, and with the usual amount of clearance between the draft key, the main part of which is numbered 6, and the walls et and The main key part o is shown provided on one end with the usual head 7 and on thc other with a hole 8 for the retainer 9. The main key part 6 is intended to extend through apertures 10 in the yoke arms 11 and to have a pulling hearing` against the surfaces 12 at the forward ends of the apertures 10. The main key part, hereinafter referred to as the key 6, has on its rear side a central radial recess 13 intended to receive the other key part, which is in the form of an equaliziug bearing 1li. The recess 13 has a central concave radial surface 15 and upper and lower concave surfaces 16, concentric to. but struck on shorter radii than, the surface 15, and connected therewith by the horizontal walls '17.

The equalizer 14 has a central forward proj lction 18 with a forward convex radial surface 19 cooperating with the key surface 153, and also convex radial surfaces 20 coo; ing with surfaces 16 on the key. As the i at. n distance between. the surfaces 19 and 2O on tirKv equalizer is substantially greater than the normal clearance between the forward face of the key 6 and the forward face a of the key slot 3, it will be seen that the key and the equalizer when they have been ay plied ,prei erly to the coupler shank will always be 1naintained in operative relationship and a full bearing between the key and its equali' c will be assured. Thus, when the coup moves rearwardly under buff the key au.,A equalizer may separate to the extent pei-irrt ted by the key slot 3 in the coupler shank. but the projection 1S of the equalizer 14; ill be engaged by the upper and lower walls i of the recess and the parts will thus be kept in the proper assembled relation.

The base of the equalizer extends laterally in the forni of shoulders 21 on either side of the equalizer' surfaces 20 and above and below the surface 19 to give an adequate bearing against the rear end of the key slot 3. To provide for lateral angling to the extent permitted by standard practice, as indicated by the broken line position of the coupler shank in`Fig. 1, so that the key will maindij tain an eqnalized hearing` against both arms ot the yoke, it is necessary to provide clearance betn'een the equalizer 14 and the key 6. "lenee, l have shown the key cut back at 22 on either side oi' the surfaces 1G and opposite the shoulders 21 on the equalizer, so as to lgive such cleafance and prevent interference to angling'. it desired, the surfaces 23 and 2li which extend either side the shoulders 2l and 22 respectively may be made so as to come into contact just n'hen the coupler is angled laterally lo its maximum position so as to afford an additional area 01"' contact betiveen the key and equalizer when the coupler is in such amjled position.

Tit desired to provide a key of additional "rn it may be made of Naro or other special stiel particularly intended to resist shear and bending stresses.

lt yvill he seen that my improved mechanism is ol particular value because ot the simplicity ot its const uction, the fewness oit its parts, and because it is adapted especially to be applied to connect the shanks ot standard D-couplers With Well-known yoke con,- strnetions Without anyT change ol any part except the key.

rl`he terms and expressions which l have employed are used terms ot description and not of limitation, and I have no intention, in the use ot such terms and expressions, Ot excluding` any equivalents ot the features shown and described, or portions thereof, but recognize that various modifications are possible Within the scope ot the invention claimed.

lVh at l claim is:

l. ln a coupler attachment, a. coupler shank having' a horizontal slot therein: a pair ol slotted yoke arms; a radial dratt key si 'ed in said slot and forming' a cratt connection betveen the shank and yoke arms, said key having` a r cess therein; and an eqnalizing member seating' in said recess nd havin gr a radial bearing` on the key in the id recess to permit the key to angle rela.- ti e to the equalizer member and equalize the draft stresses transmitted through the key to said yoke arms.

2. In a coupler attachment, a coupler shan having-j horizontal slot therein; aV yoke arms; .an-a a radia drait key seated ii said slot and formingthe connection in dra;IV between the shank and yoke arms: an eque.- iizer member ha Yino; a bearing" in the slot i the coupler and having a slot and projection engagement with said key and beiirgY c: pable oit radial movement relative thereto to permit thA arms ot the yoke to angle relatively to the coupler vhile maintaining` a full bearinfr on the coupler.

3. In a coupler attachment, a coupler shank having` a horizontal slot therein; a pair of yoke arms; and a radial draft key seated in said slot and forming the connection in draft betnr'cen the shank and yoke arms, said draft key being formed ot two parts, one ot which has a bearing on the yoke arms and the other on the coupler shank, the parts having.;` Cmmerating are-shaped bearing faces to permit the parts to revolve about each other to maintain full bearings on the coupler shank and yoke arms during' lateral angling.

lin a coupler attachment, a. coupler shank having,r a horizontal slot therein; a pair ot yoke arms; a radial draiit key seated in said slot and forming the connection in draft between the sha ik and yoke arms; and an equalizer member raving; a l caring on the coupler slank and also having` arc-shaped orvz rd `)faces struck on different radii engagingrcorresponding faces on the key to permit radial movement of the said parts during late al angling of the coupler relative to the yoke.

5. .ln a coupler attachment, a coupler shank having' a horiz ntal slot therein; a pair ot yoke arms' and a. tivo-part 'adial drat't l-:ey 'apable ot insertion as one part throi'igh the said key slot and seciiiring,- the shank and yoke arms together; the said parts being capi ble ot rotating one upon the other to permit the equalized bearing ot the key on the yoke arms when the coupler is under draft and angled laterally relative to the yoke.

(i. In railvvay draft rigging, a coupler ha ving a horizontal slot therethrough, said slot having` projecting therein a. forwardly facing convex protuberance movable with the conpler shank on draft, al yoke havinzer arms with slots therein ren'steriiigr with said first named slot, a draft key passing through all of said slots to connect said shank and yoke, the slot in the shank providiim' :a ieient clearance tor said key to enable the same to angle therein, aid key having a rearwardly facing' concave notch therein seating against and having radial bearing on said protuberance for permit-ting; horizontal angling th c rebetween.

7. ln a railvvay draftrigging, the combi nation with a eon'iler having the shank thereot provided with a transverse key receiving opening; of a yoke member having aligned coupler key receiver openings; a coupler key extending through the opening ot the shank and the openings oi the yoke; a pivot member mounted in the coupler shank, said pivot member and the rear edge ot the coupler key having interengagingg pivotal bea 'ing surfaces; and means 'for preventing accidental removal of the pivot member.

ERNEST H. SCHMIDT. 

